SANAA, Yemen >> A government warplane mistakenly bombed an army position in southern Yemen, killing at least 30 soldiers and wounding many more, military and medical officials said today.

The officials said the bombing, which took place on Saturday evening in the southern Abyan province, targeted an abandoned school used as shelter by soldiers of the army’s 119th Brigade. The school is located just east of Abyan’s provincial capital Zinjibar, where militants linked to al-Qaida have been in control since May.

Heavy fighting has been raging in the area for days as part of the army’s monthslong campaign to seize back Zinjibar from the militants.

The officials, who spoke on condition of anonymity because they were not authorized to release the information, said there were unconfirmed reports that militants arrived at the school soon after the airstrike and killed an unspecified number of wounded troops.

The school is in the Bagdar area, along the frontline between Yemeni forces and militants. On Saturday, fighting in Zinjibar killed at least 28 soldiers and militants.

The 119th Brigade has rebelled against the regime of President Ali Abdullah Saleh to join the protest movement demanding his ouster. It is thought to have received significant support from the U.S. military to enable it to fight the militants in the south more efficiently.

The airstrike is likely to hurt the morale of Yemeni soldiers as they try to battle their way into Zinjibar and other areas in Abyan under the militants’ control.

It may also raise questions about whether the bombing was a mistake since the troops that were hit had sided against Saleh in the country’s political crisis.

Forces loyal to Saleh have also been battling renegade troops from another army unit, the elite 1st Armored Division, that defected to the opposition in March, with the two sides exchanging shells and rockets across Sanaa, Yemen’s capital, for weeks now.

Yemen’s crisis began in February, when protesters inspired by Arab uprisings across the region took to the streets to demand Saleh step down after 33 years in office. Fighting also erupted between government forces and anti-Saleh tribes, and al-Qaida linked militants have taken advantage of the turmoil to overrun parts of the south.

Yemen’s turmoil is of huge concern to the United States and Europe because the country has become a haven for Islamic militants, including al-Qaida in the Arabian Peninsula, which Washington says is the most dangerous remnant of the global terror network.

The airstrike near Zinjibar came after a U.S. drone strike in the al-Jawf province to the east of Sanaa on Friday killed three key figures of Yemen’s al-Qaida branch.

The three were U.S.-born cleric and al-Qaida propagandist Anwar al-Awlaki; Samir Khan, a Pakistani-American who produced the terror group’s English-language Web magazine, Inspire; and Ibrahim al-Asiri, an al-Qaida’s bomb-maker linked to Nigerian underwear bomber accused of trying to blow up a plane over Detroit on Christmas Day 2009.

The three were traveling in a two-car convoy in eastern Yemen when the drone hit.

Tribal elders on Sunday said there may have been a third car, which escaped the strike. They spoke on condition of anonymity because they feared reprisals for speaking to the media.